Data

SQL roadmap

Query, analyze and protect relational data, from SELECT and joins to window functions, transactions and query tuning.

What you will learn

1. SQL Foundations
Query relational data with SELECT, filtering, sorting and joins.
- SQL Basics — Databases · SQL Basics
- Joins — Databases · Joins
2. SQL for Analytics
Summarize data with GROUP BY and HAVING, and answer harder questions with subqueries, CTEs and window functions.
- GROUP BY & HAVING — Databases · GROUP BY & HAVING
- Subqueries, CTEs & Window Functions — Databases · Subqueries, CTEs & Window Functions
3. SQL for Applications
Keep application data correct with transactions, ACID, isolation levels, locking and MVCC.
- Transactions & ACID — Databases · Transactions & ACID
- Isolation, Locking & MVCC — Databases · Isolation, Locking & MVCC
4. SQL Performance
Read query plans, choose the right indexes and fix N+1 queries and connection pool problems.
- Indexes & Query Plans — Databases · Indexes & Query Plans
- N+1, Indexes & Connection Pooling — Performance Engineering · N+1, Indexes & Connection Pooling

Each step unlocks when you answer its questions well enough, and a module you finish counts in every roadmap that shares it.